Java IO.pdf - Nguyen Dang Binh

Java I/O
operations from moving bytes from one device to another. Java is the first major language to
recognize and take advantage of this.
Organization of the Book
This book has 17 chapters that are divided into four parts, plus two appendixes.
Part I: Basic I/O
Chapter 1
Chapter 2
Chapter 3
Chapter 1 introduces the basic architecture and design of the java.io package,
including the reader/stream dichotomy. Some basic preliminaries about the int, byte,
and char data types are discussed. The IOException thrown by many I/O methods is
introduced. The console is introduced, along with some stern warnings about its
proper use. Finally, I offer a cautionary message about how the security manager can
interfere with most kinds of I/O, sometimes in unexpected ways.
Chapter 2 teaches you the basic methods of the java.io.OutputStream class you
need to write data onto any output stream. You'll learn about the three overloaded
versions of write(), as well as flush() and close(). You'll see several examples,
including a simple subclass of OutputStream that acts like /dev/null and a TextArea
component that gets its data from an output stream.
The third chapter introduces the basic methods of the java.io.InputStream class
you need to read data from a variety of sources. You'll learn about the three
overloaded variants of the read() method and when to use each. You'll see how to
skip over data and check how much data is available, as well as how to place a
bookmark in an input stream, then reset back to that point. You'll learn how and why
to close input streams. This will all be drawn together with a StreamCopier program
that copies data read from an input stream onto an output stream. This program will be
used repeatedly over the next several chapters.
Part II: Data Sources
Chapter 4
The majority of I/O involves reading or writing files. Chapter 4 introduces the
FileInputStream and FileOutputStream classes, concrete subclasses of
InputStream and OutputStream that let you read and write files. These classes have
all the usual methods of their superclasses, such as read(), write(), available(),
flush(), and so on. Also in this chapter, development of a File Viewer program
commences. You'll see how to inspect the raw bytes in a file in both decimal and
hexadecimal format. This example will be progressively expanded throughout the rest
of the book.
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